A novel magnet suitable for nuclear magnetic resonance (NMR) imaging has been designed, and constructed. The magnet employs windings on two hemispherical shells which can be rotated with respect to each other about two orthogonal axes. This arrangement allows prescribed large gradients in magnetic field to be superimposed on an initially homogenous field. The magnet dissipates 7.5 kw of power and has an inner spherical diameter of 0.6 m. Its two power supplies have a short term stability of better than 1 ppm over 10 seconds, and a long term stability of better than 10 ppm. The basic homogeneity of the magnetic field is about 50 ppm over a sphere of diameter 10 cms.